Pressure controller

ABSTRACT

The present device relates to a pressure controller, in particular for a slip-controlled brake system in a motor vehicle, which is equipped with a first housing ( 1 ) for the accommodation of several pressure control valves and with a second housing ( 2 ) arranged on the first housing ( 1 ) and accommodating electric and/or electronic components which electrically contact several pressure sensors arranged in a sensor housing ( 3 ) when the second housing ( 2 ) is placed on the first housing ( 1 ), and at least one device is arranged between the sensor housing ( 3 ) and the second housing ( 2 ) for the compensation of process and assembly tolerances.

BACKGROUND OF THE INVENTION

The present invention relates to a pressure controller, in particularfor slip-controlled motor vehicle brake systems.

DE 198 41 334 A1 discloses a pressure controller of this type for awheel-slip controlled motor vehicle brake system which includes a firsthousing for accommodating a plurality of electrically operable pressurecontrol valves and a second housing for accommodating electric andelectronic components. When the second housing is placed on the firsthousing, not only the pressure control valves but also a plurality ofpressure sensors arranged in a block-shaped sensor housing areelectrically contacted. The sensor housing is fluid-tightly closed by acover provided with a seal-tight electric plug to permit an electricconnection between the pressure sensors and the electric and electroniccomponents in the second housing. The sensor housing along with thecover forms an independently operable, structurally complicated pressuresensor module which must be attached in an extremely precise fashionbetween the two housings by means of clamping bolts.

SUMMARY OF THE INVENTION

In view of the above, an object of the invention is to simplify thestructure of the pressure controller.

According to the invention, this object is achieved for a pressurecontroller of the type mentioned hereinabove using a second housingarranged on a first housing and a compensation device arranged between asensor housing and the second housing to compensate for process andassembly tolerances.

Further features, advantages and possible applications of the inventioncan be taken from the description of several embodiments by way of theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a first embodiment of the invention in a partial view of apressure controller in the area of a pressure sensor module that isprovided with a separately operable housing frame;

FIG. 2 shows a second embodiment of the invention in a partial view of apressure controller in the area of a pressure sensor module, the housingframe of which is integrally connected to a first housing;

FIG. 3 shows a third embodiment of the invention in a partial view of apressure controller in the area of a pressure sensor module, the housingframe of which is integrally connected to the pressure sensor module;

FIG. 4 is an exploded view of the pressure sensor module.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 respectively show in a schematic view a pressure sensor moduleof a pressure controller in a cross-sectional side view being e.g. usedfor a slip-controlled brake system in a motor vehicle. The pressurecontroller is equipped with a block-shaped first housing 1 for theaccommodation of a plurality of electrically operable pressure controlvalves and a cover-shaped or plate-shaped second housing 2 for theaccommodation of electric and/or electronic components 5 of anelectronic control unit. The second housing 2 is placed on the pressuresensor module attached to the first housing 1. The pressure sensormodule is basically composed of a block-shaped sensor housing 3 which isflanged at the first housing 1 by means of several pressure pipes 12.

In all embodiments illustrated in FIGS. 1-3, the sensor housing 3 isdesigned as a rectangular block-shaped housing, at the plane end surfaceof which that is remote from the first housing 1 there is arranged aseal 11, pressure measuring elements 6 and a circuit board 7 that iselectrically connected to the pressure measuring elements 6. Further,several pressure pipes 12 are attached in the sensor housing 3 side byside in a row, said pressure pipes projecting in the area of a flangesurface of the sensor housing 3 that abuts on the first housing 1. Thepressure pipes 2 extend with their pipe portions 14 projecting from thesensor housing 3 into several pressure channels 13 of the first housing1 and are tightly connected to the first housing 1 by means of aso-called self-calking engagement. The pressure channels 13 are inconnection with the electrically operable pressure control valves which,preferably, control the brake pressure in several wheel brakes of amotor vehicle.

For the simple, yet reliable attachment and sealing of the pressurepipes 13 in the first housing 1 by means of self-calking engagement, thematerial of the pipe portions 14 exhibits a greater hardness than thematerial of the first housing 1. To displace the softer material of thefirst housing 1 into the recesses 16 of the pipe portions 14, the pipeportions 14 have stepped portions 18 which, in the capacity of a calkingpunch, provide an undetachable, leakproof connection between thepressure pipes 12 and the first housing 1 when the pipe portions 14 areforced into the pressure channels 13.

Likewise the pressure pipes 12 are connected to the sensor housing 3 bymeans of a self-calking engagement in an undetachable and fluid-tightfashion already before they are forced into the first housing 1, forwhat reason the material of the sensor housing 3 has a hardness lowerthan that of the material of the pressure pipes 12, which are likewiseprovided at their periphery with stepped portions for displacing thesofter material of the sensor housing 3 into the recesses 16 at thepressure pipes 12. The pressure pipes 12 are preferably made of steel,while the first housing 1 and the sensor housing 3 are manufacturedusing a light-metal alloy.

As the pressure sensor module corresponding to the previous illustrationis undetachably connected to the first housing 1, special measures needto be taken to ensure a simplest possible, fluid-tight and safeelectrical connection between the pressure sensor module and theelectric and electronic components in the second housing 2 irrespectiveof process and assembly tolerances.

In view of the above, the invention proposes that at least one means forcompensating process and assembly tolerances is arranged between thesensor housing 3 and the second housing 2, for what purpose an elasticand sealed electric contact 5 is especially appropriate that ispreferably designed as a spring contact which, when required, betweenthe sensor housing 3 and the second housing 2, is able to bridge aradial or lateral offset between the contact surfaces of the secondhousing 2 and the pressure sensor module for the purpose of tolerancecompensation.

For the sake of clarity, the illustration of an offset has been omittedin FIGS. 1-3 so that in the ideal condition the second housing 2 withits electrical point of contact in the projection 9 is aligned coaxiallyrelative to the pressure sensor module.

To seal the elastic electric contact 5, a housing frame 4 is providedbetween the sensor housing 3 and the second housing 2. The electriccontact 5 which is preferably configured as a helical spring abuts withthe end of a spring winding within the housing frame 4 on a generouslysized contact surface 16 of a circuit board 7 in a mechanically biasedmanner. The circuit board 7 accommodates the electric and/or electroniccomponents 6 necessary for several pressure measuring elements 6,received among others by a pressure signal evaluating circuit. Theresult is a unit whose function can be pre-tested before the pressuresensor module is undetachably fastened at the first housing 1.

The housing frame 4 plunges with its end area remote from the sensorhousing 3 into an elastic or plastic sealing material 8, whichcompensates the process and/or assembly tolerances and isinjection-molded into a housing groove 10 within the projection 9arranged at the bottom side of the second housing 2. A silicone gel isespecially appropriate as sealing material 8.

In order to compensate the assembly and process tolerances, the width ofthe housing groove 10 is dimensioned larger than the wall thickness ofthe housing frame 4 by a tolerance rate required therefor, with theresult of safeguarding a reliable, moisture-proof sealing of thesensitive electric and/or electronic components in the pressure sensormodule.

Following the above general description of the invention, some expedientdetails of the housing frame will now be explained more closely makingreference to the FIGS. 1-3.

In the embodiment according to FIG. 1, the housing frame 4 is designedas an independently operable component, the end area of which remotefrom the second housing 2 bears against a circumferential seal 11 at theoutside edge of the sensor housing 3. The housing frame 4 is preferablymade of an injection-molded plastic material.

Different herefrom, FIG. 2 shows a housing frame 4 which is molecularlyinterfaced with the second housing 2, and the housing frame 4, for thecompensation of process and assembly tolerances, radially displaceablyabuts on a seal 11 at the sensor housing 3 that is preferably configuredas a flat packing. The housing frame 4 along with the second housing 2is made of plastic material, preferably in an injection-moldingoperation.

In the embodiment according to FIG. 3, the housing frame 4 is integrallyconnected to the sensor housing 3, and the end portion of the housingframe 4 directed to the second housing 2 plunges into an elastic orplastic sealing material 8 that is embedded into a groove-shapedprojection 9 of the second housing 2. The housing frame 4 and the sensorhousing 3 are composed of a solid extrusion, and the housing frame 4 ismanufactured on the top side of the extrusion by means of a millingoperation.

Based on the embodiment according to FIG. 2, FIG. 4 eventually shows anexploded view for the pressure sensor module, the slim sensor housing 3of which is provided with four serially arranged bores 17 into which thefour pressure pipes 12 shown from below are pressed. The pressure pipes12 include on their top side the pressure measuring elements 6 which,after the pressure pipes 12 have been forced into the bores 17, areconnected to the circuit board 7 preferably by means of flexible contactwires. Circuit board 7 is disposed above a solid carrier plate beingrigidly interconnected after placement onto the top side of the sensorhousing 6. On the top side of the circuit board 7, an electroniccomponent 15 is arranged which comprises an evaluating circuit for thepressure signals of the pressure measuring elements 6. Further, severalcircular contact surfaces 16 arranged in a row can be easily seen on thesurface of the circuit board 7, and the electric contacts 5 which arepreferably fastened to the bottom side of the second housing 2 move intoabutment on the contact surfaces.

List of Reference Numerals

-   1 housing-   2 housing-   3 sensor housing-   4 housing frame-   5 electric contact-   6 pressure measuring element-   7 circuit board-   8 sealing material-   9 projection-   10 housing groove-   11 seal-   12 pressure pipe-   13 pressure channel-   14 pipe portion-   15 component-   16 contact surface-   17 bore-   18 stepped portion

1-12. (canceled)
 13. A pressure controller for a slip-controlled brakesystem in a motor vehicle, the pressure controller comprising: a firsthousing for accommodating one or more pressure control valves; a secondhousing arranged on the first housing for accommodating at least oneelectric component or one electronic component which electricallycontact one or more pressure sensors arranged in a sensor housing whenthe second housing is placed on the first housing; and a compensationdevice arranged between the sensor housing and the second housing inorder to compensate for process and assembly tolerances.
 14. The deviceaccording to claim 13, wherein the compensation device is an elasticelectrical contact which is arranged between the sensor housing and thesecond housing in a radially displaced manner.
 15. The device accordingto claim 14 further comprising: a housing frame (4) arranged between thesensor housing (3) and the second housing (2) for sealing the elasticelectrical contact (5) that is mechanically preloaded and abuts on acontact surface of a circuit board (7) within the housing frame (4), acircuit board accommodating the electronic components of a pressuresignal evaluating circuit necessary for at least one pressure measuringelement (6).
 16. The device according to claim 15, wherein the housingframe (4) has an end area remote from the sensor housing (3) that isimmersed into a sealing material (8) which compensates process andassembly tolerances and is inserted within a projection (9) arranged atthe second housing (2), in particular into a housing groove (10) of thesecond housing (2), a width of the groove being dimensioned larger thana wall thickness of the housing frame (4) by a tolerance rate requiredfor compensating assembly and process tolerances.
 17. The deviceaccording to claim 16, wherein the housing frame (4) is designed as anindependently operable component, the end area of which remote from thesecond housing (2) bears against a circumferential seal (11) at theoutside edge of the sensor housing (3).
 18. The device according toclaim 15, wherein the housing frame (4) is molecularly interfaced withthe second housing (2), and the housing frame (4) radially displaceablyabuts on a seal (11) at the sensor housing (3) that is preferablyconfigured as a flat packing.
 19. The device according to claim 18,wherein the sensor housing (3) is designed as a rectangular block-shapedhousing, at the plane end surface of which that is remote from the firsthousing (1) there is arranged the seal (11), at least one pressuremeasuring element (6) and the circuit board (7) that is electricallyconnected to the pressure measuring element (6).
 20. The deviceaccording to claim 19, wherein one or more pressure pipes (12) areattached in the sensor housing (3) side by side in a row, said pressurepipes projecting in an area of a flange surface of the sensor housing(3) that abuts on the first housing (1), and the pressure pipes (12)having pipe portions (14) projecting from the sensor housing (3) and arefluid-tightly connected to the first housing (1) within several pressurechannels (13) of the first housing (1).
 21. The device according toclaim 20, wherein the pipe portions (14) are comprised of a materialthat exhibits a greater hardness than a material of the first housing(1), and the pipe portions (14) have several stepped portions (18) fordisplacing the softer material of the first housing (1) into severalrecesses (16) of the pipe portions (14) which provide an undetachable,fluid-tight connection between the sensor housing (3) and the firsthousing (1).
 22. The device according to claim 21, wherein the sensorhousing is comprised of a material having a hardness lower than that ofa material of the pressure pipes (12), which are provided with severalstepped portions (18) for displacing the softer material of the sensorhousing (3) into several recesses (16) at the pressure pipes (12) whichare undetachably and fluid-tightly connected to the sensor housing (3).23. The device according to claim 20, wherein the pressure pipes (12)are made of steel, and the first housing (1) and the sensor housing (3)are manufactured using a light-metal alloy.
 24. The device according toclaim 15, wherein the housing frame (4) is integrally connected to thesensor housing (3), and the end portion of the housing frame (4)directed to the second housing (2) is immersed into an elastic orplastic sealing material (8) that is preferably embedded into agroove-shaped projection of the second housing (2).